下列哪项符合I度营养不良的诊断标准
A.体重低于正常均值10%~20%
B.精神萎靡
C.肌肉明显松弛
D.腹部皮下脂肪0.4cm以下
E.身长低于正常
参考答案:A
19.There are two buildings, ____ stands nearly a hundred feet high.
A.the larger
B.the larger of them
C.the larger one that
D.the larger of which
生产聚氨酯的主要原料有哪些?简述聚氨酯的合成原理。